Device for adjusting the light source of an electronic alignment device, operation being simplified by motorized adjustment of the light source, and a method in which this device is used

ABSTRACT

Method and device for precision adjustment of the beam direction of the light source of a device for aligning two objects relative to one another, the beam direction being moved by a motor via input elements of the computer of the alignment device.

BACKGROUND OF THE INVENTION

Field of the Invention

The invention relates to a device for adjusting the light source of anelectronic alignment device, operation being simplified by motorizedadjustment of the light source, and a method in which this device isused.

Description of Related Art

German Patent Application DE 39 11 307 A1 and corresponding U.S. Pat.No. 5,026,998, and German Patent Application DE 38 14 466 A1 andcorresponding U.S. Pat. No. 6,356,348 describe that the alignment of twocoupled shafts which, for example, connect a motor to a motor drivenpump, can be checked and corrected by means of two components of thealignment device which are attached to these shafts, the componentscontaining at least one light source, preferably a semiconductor laseror a light emitting diode, and at least one detector. A third componentwhich, likewise, belongs to the alignment device is a portable computerfor display of the misalignment and required corrections. When the twofirst-named components of the alignment device are fastened on theshafts, as a result of existing misalignment, setting of the laser beamdirection, which can be done with great precision takes place with theobjective of the laser beam striking roughly the middle of the detectorzone. This setting of the laser is performed by hand with screws andsuitable bell cranks. This is especially difficult if, on the one hand,the target of the laser beam which is mounted on the second shaft mustbe observed, and at the same time, the grips of the screws must beoperated, the components of the alignment device which contain the lasersource being located on the first shaft. This object is additionallymade difficult by poor light conditions, a rough environment and oftenpoor accessibility of the space between the motor and machine.

SUMMARY OF THE INVENTION

The invention facilitates and automates setting of the laser beamdirection relative to the at least one detector by the provision of amotorized drive for precision adjustment of the laser on the part of thedevice which contains the laser. The computer of the alignment devicewhose display represents the existing misalignment and givesinstructions for correction is designed in accordance with the inventionfor control of the motors to take place from this evaluation device viaits input device. A method in accordance with the invention which usesthis device calls for the required adjustment of the direction of thelaser beam to the middle of the detector surface to be performedautomatically under the control of the computer of the alignment deviceby means of the motors of the device after mounting of the correspondingcomponents of the alignment device on the shafts; therefore, it isperformed before the actual alignment process.

A second method in accordance with the invention comprises adjusting thedirection of the laser beam by the computer of the alignment device bymeans of the motorized drive. In the alignment process itself, if theshafts are turned into different angular positions, it is possible forthe impact point of the laser beam to reach the edge of the detector. Bymeans of this second method of adjusting the direction of the laser beamby the computer of the alignment device by means of the motorized drivewith the shaft stationary, the impact point of the laser beam againtravels nearer the middle of the detector region if it had arrivedbeforehand too near the edge of the detector.

In a third method in accordance with the invention, the direction of thelight beam is changed by the computer of the alignment device inaccordance with the invention between two predefined directions, forexample, by striking two mechanical stops. Then, the distance betweenthe two components of the alignment device is automatically determinedby the impact points of the light beam on the detector being measured inthese two predefined directions of the light beam.

The invention is described below in greater detail with reference to theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of important components of the adjustingdevice.

FIG. 2 schematically depicts an alignment device incorporating theadjusting device.

DETAILED DESCRIPTION OF THE INVENTION

Conventionally, alignment devices are fastened on shafts by a metalblock with a prismatic recess being attached to the shaft with a chain.This metal block bears two round rods which run essentially radially,but parallel to one another. The actual measurement head which isprovided with two metal pipes 13, 14, which are matched to the rods, isslipped onto these rods. When the measurement head has been moved intothe correct position, it can be fixed with screw clamps. A carrier plate11 for the components of the measurement head is fastened on the pipes13, 14. Since the pipes 13, 14 run essentially radially relative to theshaft (see the in-use orientation of the plates in FIG. 2), the y-axisof FIG. 1 for a horizontally running shaft is likewise a radiallyrunning direction. When the laser is mounted on the top of the shaft,the direction of viewing along the y-axis corresponds to a view fromoverhead or from underneath.

The light source is mounted on a separate plate 12. This light source isa semiconductor laser or a LED which is mounted in a housing 82 andwhich emits a light beam 81 in the direction of the z-axis whichcorresponds to the longitudinal axis of the shaft1. The second plate 12is securely fastened on the carrier plate 11, but can be tilted withincertain limits. In the simplified representation of FIG. 1 the carrierplate 11 has two toe bearings 21, 22. Together with these toe bearings,two holes 25, 26 form the corners of a rectangle. These holes areprovided with internal threads (not shown). From the back of the carrierplate 11, two screws 23, 24, whose tips are likewise used as bearingsfor the second plate 12, are screwed through these holes.

This plate 12 is provided with abutments 51-54 for the toe bearings.Along the edge 71 of the first plate 11, there is a support surface (notshown) on which the edge 72 of the plate 12 slidably rests. So that theplates 11, 12 can be connected to one another, they have fastenings31-34, 61-64, in which helical springs can be suspended. Thesefastenings can be, for example, hemispherical wire bows or eye bolts. Inpractice, these fastenings 31-34, 61-64 are not mounted on the surfaces73, 74 of the plates 11, 12, but on the surfaces opposite them. Thehelical springs are then routed around the small surfaces (for example,71, 72) of the plates 11, 12. FIG. 1 is a simplified representation.

At this point, if the screw 24 in the plate 11 is turned, this motionessentially causes tilting of the plate 12 around the y-axis, whileturning on the screw 23 caused tilting around the x-axis. Therepresentation in FIG. 1 is generally not implemented in this way. Onthe one hand, the carrier plate should not be drilled through, and onthe other hand, it is more useful as a result of the three-dimensionallytight conditions to operate the screws from overhead and to arrange themwith their axes accordingly parallel to the y-axis. Then, it isnecessary to convert the axial motion of the screws into tilting of theplate 12 by way of bell cranks or other suitable devices. One skilled inthe art knows suitable methods for expanding the device for tilting bysuitable support surfaces which on the surfaces 71, 72 and the other sixsmaller surfaces of the plates 11, 12 position the two plates relativeto one without producing a change in the x and z directions, when thealignment devices are turned in measurement with the shafts to whichthey are attached.

In FIG. 2, the two shafts 1, 2 and the coupling 3 which connects theseshafts are shown. A first component 15 of the alignment device ismounted on the first metal block 17 and a second component 16 of thealignment device is mounted on a second metal block 18. In the upperpart of the first component 15 is the light source 82 which emits thelight beam 81 in the direction toward the second component 16. Thissecond component 16 contains a reflector 6 which is made here as a prismwith two mirrored surfaces 6 a and which reflects the light beam 81 as alight beam 81 a back to the first component 15, where it is incident onthe detector 83 at the impact point 20. In the first component 15, thelight source 82 is mounted on the plates 11, 12 shown in FIG. 1 so thatthey can be adjusted by a motor. The motors which are located in thefirst component 15 for adjusting the plate 12 relative to the plate 11are triggered by the computer 90 of the alignment device which isconnected to the first component 15 either by a cable 91 or wirelessly.

In accordance with the invention, at this point, there is motorizedadjustment which makes it possible for personnel to undertake the oftennecessary adjustment of the laser beam relative to the desired impactpoint without touching the components 15, 16. Triggering of the motor ormotors can be done via controls which are located on the computer 90which are associated with the alignment device, the computer beingnecessary in any event for displaying of the alignment data and thenecessary corrections. Alternatively, the motorized adjustment of theimpact position of the light beam on the detector can also beautomatically undertaken by a program in the computer 90.

The invention thus makes it possible to eliminate the need for therequired precise positioning of the impact point 20 of the laser beam onthe detector to have to be done by hand (it being sufficient to alignthe laser beam relative to the detector only roughly by hand), after thefirst fastening of the metal blocks 17, 18 on the shafts 1, 2, andtherefore, before the start of the actual alignment measurement. Theexact alignment of the light source in the component 15 can take placein accordance with the invention in that the alignment computer 90produces adjustment of the plates 11, 12 relative to one another by amotor until the impact point 20 comes to rest in a given middle regionaround the center of the detector 83. The size of this middle region canbe, for example, 20% of the area of the detector 83.

In another aspect of the invention, motorized adjustment is used towiden the measurement range of the detector. In order to determine thealignment, it is necessary for the shafts 1, 2 to be turned intodifferent positions with the metal blocks 17, 18 and the components 15,16 mounted on them. This rotation is indicated in FIG. 2 by the curvedarrows surrounding the shafts 2, 3. As a result of this rotation, it canhappen that the impact point 20 leaves the usable surface of thedetector 83. Then, according to the prior art described in U.S. Pat. No.6,040,903, it is necessary to change the position of one of the twocomponents 15, 16 and the metal blocks 17, 18 which bear them on therespective shaft by turning the respective component and the metal blockwhich bears it around the shaft such that impact point 20 on thedetector 83 again comes to rest near the middle of the detector 83.

The motorized adjustment in accordance with the invention now makes itpossible to track the light beam, and thus, the impact point 20 withoutintervening in the mounting of the components 15, 16 on the shafts 1, 2when the impact point 20 has reached the edge region of the detector 83.The size of the edge region can be 10% or 5% of the area of thedetector. A program in the computer 90, using the preceding movement ofthe impact point 20 on the detector 83 which has been caused by therotation of the shafts 1, 2, computes in which direction and by whichamount the direction of the light source must be adjusted and causes thecorresponding adjustment by triggering the motors, and thus, acorresponding relative displacement of the plates 11, 12. When theimpact point 20 has then come to rest again in a given region around thecenter of the usable surface of the detector 83, rotation of the shafts1, 2 can continue, as can the actual measurement of alignment.

A third method calls for changing the position of the light beam on thedetector 20 in a defined manner, for example, by moving from a firststop to a second stop. This changing of the direction of the laser beamby a defined angle makes it possible to compute the distance between thecomponents 15, 16 using the resulting change of the position of theimpact point 20 with simple geometrical methods. This computation canadvantageously take place in the computer 90 of the alignment devicewhich also triggers the motors for this distance determination.

The motors which are necessary for adjustment can be of various types,depending on the type of adjustment device used for the plate 12. If, asshown in FIG. 1, screws are used for tilting of the plate 12, the motorscan be rotating motors whose shaft is provided with an outside thread.If, as described above, bell cranks are used, the screws can be replacedby suitable motors which execute linear motion. Linear motors candirectly replace the screws, even if there are no bell cranks.

In general, piezomotors are preferred for carrying out the invention. Inone especially preferred configuration, linearly acting piezomotors areused.

Of course, the invention is not limited to the use of carrier plates,the replacement of screws by motors or the connection of the carrierplates by springs. A plurality of other measures will be apparent to oneskilled in the art from the foregoing with which precision adjustment ofthe beam direction of a laser can be effected in accordance with theinvention.

In the measurement head which contains the laser, a battery compartmentis contained anyway to supply the laser and the interface forcommunication with the computer. From there, power can also be suppliedfor operating the motors for alignment of the lasers.

Furthermore, the subject matter of the invention is that triggering ofthe motors is not undertaken on the measurement head itself, but on thecomputer 90 which is an existing part of alignment devices so that suchneed not be added to implement the invention. The computer 90 isconnected to the measurement head via electrical lines or wirelessly.This connection is used, for example, to transmit information which isto be modulated onto the laser beam, or if there is a detector in themeasurement head, for transmission of the measured values of thedetector to the computer of the alignment device.

It is possible via this connection to transmit data from the computer ofthe alignment device to the measurement head, which data indicate to themeasurement head which motor is to be operated, in which direction thismotor is to run and how long it is to run. These portable computers areprovided with cursor keys, four-way buttons or other input means such asa mouse, touchpad, trackstick, trackball or joystick. The motors in themeasurement head with the laser are triggered via suitable software ininterplay with these input devices. Of course, as described above, thedirection of the light beam can also be changed by the computer itselfvia a corresponding program.

In the adjustment of the direction of the light beam controlled viacontrols, the user of this alignment device can easily observe andinfluence the impact point of the laser beam without awkwardly having toobserve the impact point with his eyes in the vicinity of themeasurement device on the shaft, and on the other hand, having to adjustpoorly accessible screws in this attitude in a very sensitive manner.When the laser first strikes the detector element, a display of theimpact point on the display of the computer is also easily possible sothat direct observation in the vicinity of the measurement head on thesecond shaft is no longer necessary.

It goes without saying that the invention can also be advantageouslyused with types of alignment devices other than the embodiment shown inFIG. 2. Thus, there are alignment devices in which in one of the twocomponents 15, 16, there is a light source and in the other, there areone or two detectors located in succession in the beam path. In againother alignment devices, in each of the two components 15, 16 there area respective light source and a detector that the light source anddetector are opposite one another in pairs. In the latter embodiment,the beam adjustment in accordance with the invention can be used for oneor for both light sources.

What is claimed is:
 1. Method for adjusting a laser beam of an alignmentdevice, comprising the steps of: respectively mounting first and secondcomponents of the alignment device in a fixed position on an outersurface of first and second rotatable shafts of machine parts that areoperatively connected to each other by a coupling and the alignment ofwhich is to be detected, wherein a laser device and motors are locatedin at least one of the first and second components of the alignmentdevice and wherein the motors are connected to a support of the laserdevice to adjust the position of the laser device within the componentin which the laser device is located and the position of the laserdevice on the rotatable shafts to be aligned with respect to each other,the motors being connected to a computer of the alignment device in amanner enabling the computer to control operation thereof for settingthe position of the laser device for causing an impact point of thelaser beam to be located in a predefined region that is near a center ofa detector that is positioned for receiving said laser beam; using thecomputer of the alignment device to adjust an emission direction of thelaser beam from the laser device located within said at least one of thefirst and second components of the alignment device so as to position animpact point of the laser beam in a predefined region of the detectorthat is near a center of the detector, the computer causing the motorsconnected to the support of the laser device within the component inwhich the laser device is located to adjust the position of the laserdevice on the shafts the alignment of which is to be detected inresponse to impinging of the laser beam at an impact point outside ofsaid predefined region; and then, commencing detection of the state ofalignment of the shafts relative to each other.
 2. Method in accordancewith claim 1, wherein control commands for triggering the motors aretransmitted to the motors via controls of the computer.
 3. Method inaccordance with claim 1, wherein control commands for triggering themotors are transmitted to the motors from a program in the computer. 4.Method in accordance with claim 1, comprising the further steps of:during detection of the state of alignment of the shafts relative toeach other, determining when the impact point of the light beam reachesa predefined edge region of the detector, using the computer to triggerthe motors to adjust the emission direction of the laser device beam tore-position the impact point of the laser beam on the detector to thepredefined region of the detector near the center.
 5. Method inaccordance with claim 4, wherein control commands for triggering themotors are transmitted to the motors via controls of the computer. 6.Method in accordance with claim 4, wherein control commands fortriggering the motors are output to the motors from a program in thecomputer.
 7. Method in accordance with claim 1, wherein the adjusting ofthe emission direction of the laser beam moves the laser device by apredefined angle, and wherein the computer determines the distancebetween the laser device and the detector from a displacement of theimpact point of the laser beam on the detector which has been caused bythe adjusting of the emission direction of the laser device. 8.Alignment device, comprising the following: a computer; first and secondcomponents and parts configured for mounting the first and secondcomponents in a fixed position on an outer surface of a respective oneof first and second shafts of rotatable machine parts which are to bealigned with respect to each other, at least the first component havinga laser device for radiation of a laser beam located therein and atleast one of the first and the second component having a detector orreflector upon which the laser beam is to impinge; wherein motors withinthe component in which the laser device is located are connected to asupport of the laser device to adjust the position of the laser devicewithin the component in which the laser device is located on the shaftsto be aligned with respect to each other, the motors being connected tothe computer in a manner enabling the computer to control operationthereof for setting the position of the laser device for causing animpact point of the laser beam to be located in a predefined region ofthe detector that is near a center of the detector in response toimpinging of the laser beam at an impact point outside of saidpredefined region.
 9. Device in accordance with claim 8, wherein inputelements of the computer of the alignment device are entry elements fortriggering the motors.
 10. Device in accordance with claim 8, whereinthe computer has a program for triggering of the motors.
 11. Device inaccordance with claim 8, wherein at least one of the motors is a linearmotor.
 12. Device in accordance with claim 8, wherein at least one ofthe motors is a piezomotor.